The present invention relates to connectors for electrically and mechanically linking circuit boards, and to assemblies of multiple interconnected circuit boards.
The use of circuit boards of memory, logic and other circuitry is well known in the data processing field. The interconnection of multiple circuit boards is particularly advantageous in connection with large scale computers, where space for electrical circuits is at a premium, and the shortest possible electrical paths between and within discrete circuits are desired.
One particularly useful interconnection of multiple circuit boards is an orthogonal mounting of a "horizontal" stack of circuit boards to an adjacent "vertical" stack. This arrangement occupies a minimum of space, and permits direct contact between each board of one of the stacks with every board of the other stack. Further, each electrical connection is through a short conductive path, significantly reducing travel time for electric signals for a corresponding reduction in time to perform various operations.
Orthogonal arrangements, however, require special devices for effecting electrical and mechanical connection between the multiple circuit boards. For example, U.S. Pat. No. 4,472,765 to Hughes granted Sept. 18, 1984 shows a row of zero insertion force electrical connectors 7 connected to a row of perpendicular zero insertion force connections 17, through a mother board 4. Pins from connectors 7 and 17 are inserted through openings in the mother board, with certain pins from each connector pressed into holes in diamond-shaped conductive areas 40, thus to electrically link various connectors. U.S. Pat. No. 3,660,803 to Cooney granted May 2, 1972 shows a connector 20 with a longitudinal slot that supports a circuit card 11. On the opposite side, connector 20 has contact elements 70 and 90 for connection with a memory stack 60 normal to circuit cards 11.
Joining multiple boards, whether or not orthogonally, involves further problems due to the multiplicity of electrical pin contacts and mating socket contacts involved in the connection. Any misalignment can cause failure to accomplish electrical contact, and can damage the pin contacts. One approach to this problem has been the zero force connector mentioned in Hughes, yet such connectors are relatively expensive.
An individual connector between parallel circuit boards is shown in U.S. Pat. No. 4,482,937 to Berg granted Nov. 13, 1984. Pairs of substantially identical, oppositely oriented housing members 30 and 90 are positioned between parallel circuit boards 5 and 65. Each of the housings has a projection 36 and an associated alignment cavity 37, with apertures 32 and 34 for sockets and pins, respectively. On a much larger scale, a four pole coupler for a dynamic loudspeaker is described in U.S. Pat. No. 2,124,207 to Neesen granted July 19, 1938. Opposed plug and socket members have circular contact faces divided into alternating pie-shaped extended and retracted surfaces. Female contacts are mounted in the extended surfaces, while male contacts extend from the recessed surfaces. The arrangement protects the male contacts and ensures proper connection.
The plug and socket disclosed in the Neesen Patent are complementary, yet differ in structure. Consequently, such plug/socket design, when applied to the micro scale of circuit board interconnection, raises three problems:
(1) The potential for error due to mounting of a socket where the intention was to mount a plug;
(2) The lack of flexibility resulting from having to choose either the plug or socket; and
(3) The need to keep inventories of both plugs and sockets as spare parts.
Further, the Neesen design fails to avoid the alignment and insertion force problems caused by multiple connections.
It therefore is an object of the present invention to provide a connector structure simple in design and adapted to facilitate multiple circuit connections by pre-aligning mating pin and socket contacts.
Another object of the invention is to provide a single connector structure used as both a plug portion and socket portion of a connecting device.
Another object of the invention is to provide a single connector structure mounted to all of the circuit boards in an orthogonal mounting scheme, and which ensures orthogonal mounting.
Yet another object of the invention is to provide an assembly of orthogonally mounted circuit boards, based on a single type of connector, with each connector mounted in an identical orientation with respect to its associated one of the circuit boards.